Field of the Invention Description
The present invention relates to sweetness receptor antagonists which are useful for the prophylaxis or treatment of metabolic syndrome, diabetes, obesity, and the like.
Discussion of the Background
A sweetness receptor (T1R2/T1R3) is present in oral taste cells, and is known as a receptor to perceive sweetness. In recent years, it has been reported that a sweetness receptor is expressed not only orally but also in the intestine and pancreas (see Proc. Natl. Acad. Sci. USA., 2007, 104, 15075-15080 and PLOS ONE, 2009, volume 4, issue 4, e5106, both of which are incorporated herein by reference in their entireties). A sweetness receptor is also expressed in preadipocyte line 3T3-L1, and is being clarified to be involved in adipogenesis. Therefore, a sweetness receptor antagonist may become a promising target as a therapeutic agent for metabolic syndrome, diabetes, obesity and the like (see PLOS ONE, 2013, volume 8, issue 1, e54500 and Journal of Biological Chemistry, 2013, 288, 32475-32489, both of which are incorporated herein by reference in their entireties).
As sweetness receptor antagonists, inorganic compounds such as zinc sulfate, copper chloride and the like, as well as the organic compounds represented by the following formulae:
have heretofore been known (see Journal of Medicinal Chemistry, 2009, 52, 6931-6935, which is incorporated herein by reference in its entirety).
On the other hand, American Journal of Primatology, 2004, 62, 43-48, which is incorporated herein by reference in its entirety, describes that a compound represented by the following formula:
(SC-45647) has a sweetness receptor agonist activity.
Moreover, WO 2006/084184, which is incorporated herein by reference in its entirety, discloses that a compound represented by the following general formula:
has a sweetness receptor agonist activity.
Furthermore, WO 2012/121273, which is incorporated herein by reference in its entirety, discloses a compound represented by the following general formula (I):
wherein each symbol is as defined in WO 2012/121273, as a saltiness enhancer.
Furthermore, Journal of Medicinal Chemistry, 1992, 35, 1747-1751, which is incorporated herein by reference in its entirety, describes a compound represented by the following formula:
wherein R═SO3Na, as a sweetness antagonist.
However, none of the above-mentioned publications describes or suggests that a compound represented by the following formula (I) of the present invention has a sweetness receptor antagonist activity.